IYTU our solar system only?

[coliver988]

Has anyone come up with a travel time program from Earth to the various planets at 1G through 6G possibly. Love the idea.

Book 2 has travel times listed for various distances (1K, 10K, 100K, etc kilomters; so if you know the distance you can get there).

Or, since CT implies constant acceleration (accelerate to the halfway point, decelerate the 2nd half) there are formulas out there on the same page:

T = 2 * sqrt(D/A)
D = AT^2 / 4
A = 4D/T^2

where T = time, D = distance, A = acceleration.

All pretty simple to plug into a spreadsheet or calculator.

 

[Chaos]

I think to a certain degree we can ignore the movement of the planets when calculating travel time.

Say, you travel from Earth to Mars. That would be, IIRC, 50 to 400 million km or so depending on their respective locations, in a straight line assuming they both stood still; I haven´t done the precise math but depending on acceleration that is between 16 and 40 hours for the shortest distance, and between 48 and 120 hours or so for the longest distance.

Mars moves along its orbital path with a speed of 24 km/s, or roughly 2.05 million km/d. So at the shortest distance, it has moved between 1.3 and 3.45 million km in the time it takes to reach its original position, for the longest distance it moved between 4.1 and 10.4 million km. Those distances are relatively small in relation to the distance travelled, and I think can be ignored for the purpose of playing a role-playing game.

 

[Vile]

As I mentioned in another thread, astronomy programs - including some available as freeware - can do this for you.

Yes, but enquiring minds want links!

 

[Mithras]

I just used the Traveller ship design rules but changed the jump drive to an interplanetary drive rated in Gs - jump 1 becomes 1G, jump 2 is 2G etc - and keep the jump fuel required as the reaction mass for 4 weeks operation.

The regular m drive becomes an orbital drive for use near planets/stations etc.

Man! That's what I did years ago! It may not be 100% accurate in terns of rocket-science, but it feels right....

 

[Mithras]

Ummmm... if there is no FTL, then there are no Travellers... thus it isn't "Traveller".

It may still be a Sci-Fi RPG, and you could even use the rules set, but it won't be the same game.

C'mon, single-system Traveller - heard of Firefly? Yep, no adventure opportunities, no 'travelling'

 

[robject]

C'mon, single-system Traveller - heard of Firefly? Yep, no adventure opportunities, no 'travelling'

And what about the early Terran Confederation milieu? That's Traveller, all bottled up in one system.

 

[aramis]

C'mon, single-system Traveller - heard of Firefly? Yep, no adventure opportunities, no 'travelling'

and an exceedingly unlikely system it be, having 5 stars, at least 4 GG's, and 25+ inhabited worlds, of which several are sub-4 Size... o:

It may just be Joss' TU, (and all those breathable sub-martians occur almost exclusively in Traveller for the games of the era) but even as a traveller system, it's bloody unlikely.

It is, however, an example of a well developed semi-fantasy TU.

 

[Daneel Olivaw]

and an exceedingly unlikely system it be, having 5 stars, at least 4 GG's, and 25+ inhabited worlds, of which several are sub-4 Size... o:

It may just be Joss' TU, (and all those breathable sub-martians occur almost exclusively in Traveller for the games of the era) but even as a traveller system, it's bloody unlikely.

It is, however, an example of a well developed semi-fantasy TU.

This aspect of Firefly's setting always gnaws at my authenticity bone. I wonder why, when a TV series creator wants many Earth-like worlds in his setting, he insists on keeping them all in one system? Especially when he appears to have gone for a fairly high degree of realism (for TV) in his portrayal of space travel (no sound, Newtonian movement, etc.). Why not maintain the sense of realism by spreading them across a cluster of systems? Isn't hyperspace or wormhole travel a more generally accepted conceit than dozens of Earth-like worlds in one star system?

Meanwhile, back on Earth, I was just given Transhuman Space and several supplementary books for Father's Day. I don't know if I'll ever play THS itself - I'm shying away from rules-heavy RPGs in general - but it sure provides a lot of good information and inspiration for a Solar System setting! One thing though, I'm not as interested in the transhumanist stuff as I am in the space stuff. While I agree with David Pulver's premise that humanity will continue to develop the ability to screw with itself on a fundamentally biological level, blurring the distinctions between man and machine, natural and artificial, MTU would tend not to focus on this aspect of life in the next century or two. I prefer more of a Charles Sheffield/Ben Bova setting.

 

[aramis]

The transit drive he describes is NOT newtonian; it caps at (IIRC) 1PSL, and is an N-space warp of some kind. It also appears to require being a distance away from the planet first...

 

[boomslang]

This aspect of Firefly's setting always gnaws at my authenticity bone. I wonder why, when a TV series creator wants many Earth-like worlds in his setting, he insists on keeping them all in one system?

Joss Whedon has explained that he explicitly did not want to mess about with FTL because he is fundamentally a non-gearhead, non-traditional-sci-fi type and he wanted a limited, bound setting. He explicitly wanted no aliens whatsoever for similar ideological reasons. He didn't care about the realism; he wanted to focus on his characters and their stories exclusively.

So we got a completely implausible setting filled with really interesting people.

Which is typical for Whedon, actually; just wait until Dollhouse premieres...

 

[Daneel Olivaw]

He didn't care about the realism; he wanted to focus on his characters and their stories exclusively.

T'is odd, then, that he chose to portray the silence of space (notwithstanding the final charge in the Serenity movie), and to have ships perform retrograde orbital/aerobraking maneuvers when descending towards a planet's surface. (I'm thinking of the first Reaver encounter; there may be more, but I haven't watched the DVDs in a while.) Maybe his production staff were more gearheaded than he and they squeezed as much realism into the effects as they could.

 

[boomslang]

Maybe his production staff were more gearheaded than he and they squeezed as much realism into the effects as they could.

Or, as I suspect, it was just cheaper to produce the SFX scenes MOS under the guise of "realism"...

 

[aramis]

MOS?

As to his production staff, he seems to have encouraged their gearheadism.

 

[boomslang]

MOS?

Ah, pardon my jargon.

MOS = old post-silent-era German acronym for "without recorded sound"; today often used in exterior location work, especially in places that are too noisy or too hard to mic properly -- you just dub ("loop") the dialog in later...

Foley (dubbing-in incidental sound effects) is expensive and time-consuming, too; it's cheaper to just dump the CGI straight into the working edit and not bother with whooshes and booms and all that... the person who does all that will be Union (with the official professional title of "Foley Artist", no kidding -- to their credit, some of them are indeed geniuses), and that means a preset minimum payday, even if it's only for a couple of clicks or beeps...

 

[castiglione]

If you're interested in a solar system only adventure, check out the expanded solar system map plus rules for moving planets over at www.boardgamegeek.com under "Triplanetary".

The map isn't completely accurate (the distances for the furthest planets are somewhat compressed) but it's a good start if you want to keep things paper and pencil'ish.

 

[tim_manley]

I ran an in solar system campaign many years ago (umm... early 90s I think) that lasted for about 2 years.

I did exactly the same thing, fully fleshed out solar system, no anti-gravity, no magic drives, all rockets.

The solar system I used was a made-up one, not our own.

I uses a distance, calendar, random die roll to determine actual distance instead of determining actual location via rotational dynamics. You were at X, wanted to leave at date Y, to go to Z, your distance is n+some random die roll. I still did the x,y,z math for travel time.

the game lasted so long and was so successful I've tried re-creating it a couple of times.

One time was in our own solar system, thinking that with all the data of orbital bodies it would be easier. I had tried to find a utility that would have the x,y,z coords of all orbital bodies in our solar system, allow anyone to input a date, and have it tell you the coords.

You can get the coord data from nasa (and just turn it into x,y,x) but the utility never materialized. My player group broke up and that game just fell silent after about 8 months.

About a year ago I started up the mechanism again, looking at a trinary system, with all 3 stars having orbital planet rings. They were core, corder and outland (inner star, 2nd star, far star).

For my ship rules life support, power plants, food, water, and fuel were all a big deal. Ships had a range based on how much air, food and water they could carry.

I've got them integrated into a home-grown house rules sytem of traveller. I won't share that one since I liberally used traveller (re-writing the LBBs) but I can parse out my ship rules and post 'em if anyone is interested

 

[tim_manley]

Man! That's what I did years ago! It may not be 100% accurate in terns of rocket-science, but it feels right....

Woah! Awesome idea!

background -- I don't play the radio when I commute, so instead I'm lost in my thoughts for my drives. One of these was steampunk travller and how 'as is' it could fit neatly into this.

I looked at the subsector map (in my head of course, not while I was driving) and saw that if I just took a big yellow dot in the center hex I had a solar system. Each hex became 1AU. All planets can be made per the rules or heck, just from http://signalgk.com/cgi-bin/ctsg.pl.

All drives work on aether, jump drives are now "slipstream" and move at jump rating of AU per week. The fuel needed is water for the boiler...

The manuever drive is just your atmo engine now...

power plant is your generator that works off your slipstream boiler....

planets don't rotate (makes it easier) or they all rotate at the same speed (heck, aether is real isn't it?).

Sure, there's some elements here that aren't hard science, but same goes for OTU....

And, damnable if you can't have a hefty piece of adventure in this with wooden ships and iron men in space....

 

[Mithras]

OK. I've produced some rules modifications for producing STL ships for my proposed solar system campaign. I've modified MOngoose Traveller. I've made certain assumptions. I'm going for a TL 10-11 feel, obviously without grav technology.

I've gone for the fission powerplant option, my game is 2380AD, plus it feels right. My main engines are fusion rockets (http://space.newscientist.com/article.ns?id=dn3294&print=true), giving acceleration from 0.2 to 1.2G (the Jump drive stands in for the fusion drive, each Jn x 0.2G).

I've resolved the problem of planetary bodies moving constantly to produce wildly varying distances to destinations.

I want to know about fuel. In this setting, I don't know, 100 tons of liquid hydrogen just doen't feel right. I've got a yearning to go toward to Deuterium/Helium3 pellets as proposed for the Daedalus project (http://en.wikipedia.org/wiki/Project_Daedalus). Helium3 is rare on Earth, probably common on the Moon and other satellites, and in the atmospheres of gas giants. But all fuel would then be 'refined' i.e. processed, and packaged into D/He3 pellets.

Anybody have any ideas on fuel for an STL campaign with fusion rockets?

 

[tim_manley]

OK. I've produced some rules modifications for producing STL ships for my proposed solar system campaign. I've modified MOngoose Traveller. I've made certain assumptions. I'm going for a TL 10-11 feel, obviously without grav technology.

I've gone for the fission powerplant option, my game is 2380AD, plus it feels right. My main engines are fusion rockets (http://space.newscientist.com/article.ns?id=dn3294&print=true), giving acceleration from 0.2 to 1.2G (the Jump drive stands in for the fusion drive, each Jn x 0.2G).

I've resolved the problem of planetary bodies moving constantly to produce wildly varying distances to destinations.

I want to know about fuel. In this setting, I don't know, 100 tons of liquid hydrogen just doen't feel right. I've got a yearning to go toward to Deuterium/Helium3 pellets as proposed for the Daedalus project (http://en.wikipedia.org/wiki/Project_Daedalus). Helium3 is rare on Earth, probably common on the Moon and other satellites, and in the atmospheres of gas giants. But all fuel would then be 'refined' i.e. processed, and packaged into D/He3 pellets.

Anybody have any ideas on fuel for an STL campaign with fusion rockets?

I did mine this way:

I used number of squares (easy measurement) for ship size (still 2 squares per ton).
Rockets provided thrust based on how many squares they could push at 1G and fuel was consumed by the rockets. The quality and type of fuel gave GHours of thrust.

Rocket       1G	
Micro       10Sq	
standard-R5 30Sq	
standard-R6 35Sq	
standard-R7 40Sq	
nuclear     45Sq	
fusion      50Sq	
ion         10Sq

I used the MT G-Hour concept for how many g-hours of thrust you got per square of fuel, and it was based on fuel type:

Fuel Type     GHour/Sq
Unrefined       10
Refined         20
Toxic           30
Exotic          50
exotic/toxic   100

Since this was all STL and in a single star system smaller ships tended to be the norm. So for example if a player had a 60 square ship with a standard R6 rocket they'd get 1.7G of thrust. If they used refined fuel for they'd get 20 hours of thrust at 1.7g for every square of fuel.

But, as I found out running this my players pretty much damned near revolted when they were confronted with even doing this level of math. So I wrote spreadsheet formulas to do everything and make it as math free as possible. Now I love the nitty gritty detail (man-days of air, food, water, hours of fuel use, etc.) But, as I age, I realize that while I may like the minute details it's really about the narration; and that's what makes the games fun.